Non-metallic expansion/deflection coupling modules

ABSTRACT

An improved device for coupling rigid non-metallic conduits is disclosed. The claimed device is capable of allowing movement in an axial direction due to expansion and contraction and can also compensate for angular or parallel deflection of the conduits.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/482,497 filed May 4, 2011, incorporated herein by reference inentirety.

FIELD OF THE INVENTION

The present invention is generally directed toward a device for joiningelectrical conduits. More specifically, it is directed toward anexpansion and deflection coupling that allows a greater range ofmovement of the conduits relative to each other.

BACKGROUND OF THE INVENTION

When joining two pieces of electrical conduit together, a simplestraight coupling is sufficient if the conduits are in axial alignment,and a rigid connection is acceptable. However, at junctions where thetwo conduits do not line up perfectly, such as in instances of axialmisalignment or parallel misalignment, angled couplings are required tojoin the conduit together.

Certain installations further require that the coupling be flexible inorder to accommodate movement. For example, a flexible conduit may berequired where a raceway crosses a structural joint intended forexpansion, contraction or deflection, such as in buildings, bridges,parking garages, or across adjacent sections of pavement. Conduitcouplings that are installed in these locations need to be able to flexin order to accommodate the movement due to changes in temperature andthe weight of vehicles. Currently available couplings have limitedability to adjust for axial expansion and contraction movements.Furthermore, prior known expansion and deflection couplings do not offeran increase in movements when being installed on site. If a greaterrange of movement is desired, the device has to be custom designed forthis at the factory.

The presently disclosed conduit couplings are able to provide a widerrange of axial and angular movement than was previously available.

SUMMARY OF THE INVENTION

A new coupling device that allows greater range of motion is disclosed.The coupling device can accommodate axial expansion and contraction, aswell as angular and parallel deflection. The claimed device is alsocapable of angular movements while expanding/contracting withoutresulting in a decreased inner diameter. The claimed device isconstructed in a modular fashion such that additional couplings can beadded to further increase the range of motion.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages of the invention will become apparent by reference tothe detailed description of preferred embodiments when considered inconjunction with the drawings:

FIG. 1 depicts a perspective view of the claimed device in an angledformation with a rigid center joint.

FIG. 2 depicts a perspective view of the claimed device in a linearformation.

FIG. 3A depicts the claimed device with a boot surrounding the joints.

FIG. 3B is a cross sectional view of the claimed device as viewed alongline 3B-3B of FIG. 3A.

FIG. 4A depicts an elevation view of the claimed device without an outerjacket.

FIG. 4B is a cross sectional view of the claimed device without an outerjacket as viewed along line 4B-4B of FIG. 4A.

FIG. 4C is another view of the claimed device without an outer jacket.

FIG. 5A depicts an elevation view of another embodiment of the claimeddevice with an outer jacket.

FIG. 5B s a cross sectional view of the claimed device with an outerjacket as viewed along line 5B-5B of FIG. 5A.

FIG. 5C depicts a perspective view of an embodiment of the claimeddevice with an outer jacket.

DETAILED DESCRIPTION

The following detailed description is presented to enable any personskilled in the art to make and use the invention. For purposes ofexplanation, specific details are set forth to provide a thoroughunderstanding of the present invention. However, it will be apparent toone skilled in the art that these specific details are not required topractice the invention. Descriptions of specific applications areprovided only as representative examples. Various modifications to thepreferred embodiments will be readily apparent to one skilled in theart, and the general principles defined herein may be applied to otherembodiments and applications without departing from the scope of theinvention. The present invention is not intended to be limited to theembodiments shown, but is to be accorded the widest possible scopeconsistent with the principles and features disclosed herein.

Referring to the drawings, FIG. 1 illustrates one embodiment of theinvention. The device consists of a male end 2 and a coupling end 1. Themale end 2 is configured such that it can be inserted into the standardbell-end of a rigid non-metal conduit. At the opposite end of thedevice, coupling end 1 is configured to receive the male end 2 of arigid non-metallic conduit. The coupling end 1 may be secured to therigid non-metallic conduit through the use of adhesive, such as PVCcement.

An inner sleeve 4 is located between the coupling end 1 and the male end2 of the device. As can be seen from FIG. 3B, the inner sleeve 4 has aninner diameter large enough for the conduit to accommodate the wiresthat pass through it. The diameter of the inner sleeve 4 is larger atthe ends than in the middle of the inner sleeve 4. At the male end 2 ofthe coupling, the larger end of the inner sleeve 4 is housed within maleend adapter sub-assembly 3. As can be appreciated from FIG. 3, this maleend adapter sub-assembly 3 partially surrounds the larger end of innersleeve 4. The diameter of male end adapter sub-assembly 3 is larger thanthe diameter of inner sleeve 4, but smaller than the larger end of innersleeve 4. As a result, inner sleeve 4 can move axially relative to themale end 2 of the coupling, or it can pivot within male end adaptersub-assembly 3. The inner surface of the male end adapter sub-assembly 3may be a curved surface. The male end 2 of the inner sleeve 4 may alsohave a surface that is curved inward toward the axis of the inner sleeve4. The angle of curvature of each of the two curved surfaces is selectedso that contact between the edge of the inner sleeve 4 and the innersurface of the male end adapter sub-assembly 3 is minimized. Thecurvature of the two surfaces allows the coupling to accommodate greaterangular movement of the inner sleeve 4 relative to the conduit even asthe coupling is simultaneously accommodating axial movement of theconduits.

A similar range of motion exists between the inner sleeve 4 and thecoupling end 1 of the device. At the coupling end 1 of the device, thelarger end of inner sleeve 4 is housed within coupling end adaptersub-assembly 5. As can be appreciated from FIG. 3B, this coupling endadapter sub-assembly 5 partially surrounds the larger end of innersleeve 4. The diameter of coupling end adapter sub-assembly 5 is largerthan the diameter of inner sleeve 4, but smaller than the larger end ofinner sleeve 4. As a result, inner sleeve 4 can move axially relative tothe coupling end 1 of the coupling, or it can pivot within coupling endadapter sub-assembly 5. The inner surface of the coupling end adaptersub-assembly 5 may also be a curved surface. The coupling end 1 of theinner sleeve 4 may also have a surface that is curved inward toward theaxis of the inner sleeve 4. The angle of curvature of each of the twocurved surfaces is selected so that contact between the edge of theinner sleeve 4 and the inner surface of the coupling end adaptersub-assembly 5 is minimized. The curvature of the two surfaces allowsthe coupling to accommodate greater angular movement of the inner sleeve4 relative to the conduit even as the coupling is simultaneouslyaccommodating axial movement of the conduits.

In one embodiment, inner sleeve 4 may be one solid piece, as depicted inFIGS. 1 and 2. In another embodiment, multiple inner sleeves 4 may bejoined together using one or more center joint 7, as depicted in FIG. 3.Center joint 7 allows an even larger range of motion, both in an axialdirection and angularly. As can be seen from FIG. 3B, center joint 7 hasa convex inner surface such that the larger ends of inner sleeve 4 aretrapped within it due to the smaller diameter at the outer surface ofthe center joint 7 relative to the middle of center joint 7.

As can be appreciated from FIG. 3B, in a preferred embodiment, the innersurfaces of the inner sleeve 4 are smooth and void of sharp edges. Thesmooth surface prevents the wires from being pinched as the couplingflexes and moves to accommodate the stresses of its environment. Thesmoother inner surfaces also allow the wires to move within the couplingwithout becoming snagged or restricted by an interior edge.

The disclosed coupling has a significantly greater range of motion inboth the axial and angular directions compared to other known couplingdevices. As a result, the device can be used where axial expansion orcontraction is anticipated, where there is angular movement betweenconduits, or where there is parallel deflection between the conduits. Itshould be appreciated that the inner diameter of the disclosed couplingdoes not decrease as the coupling moves. The wires, therefore, do notget pinched as the coupling moves.

Due to the modular construction of the device, multiple couplings may bedirectly attached to each other to achieve an even greater range ofmotion. To connect one coupling to another, the male end 2 of one deviceis inserted into coupling end 1 of a second device. The modularconstruction of the couplings allows the wires that pass through it tobe protected as the building, bridge, or other structure moves in anydirection and over any distance. It should be appreciated that themodular construction further allows the device to simultaneouslyaccommodate movement in the axial direction and angularly from anydirection, not just one fixed direction.

In one embodiment, as shown in FIGS. 3A and 3B, the disclosed device mayadditionally include a boot or jacket that surrounds the hubs at bothends of the coupling. The boot may be made of rubber or neoprene, or anyother flexible material that can be used to create a water-tight seal.The boot may be secured to the exterior surfaces of the coupling endadapter sub-assembly 5 and the male end adapter sub-assembly 3 by use ofjacket strap 8, preferably a stainless steel tamperproof strap orplastic ties, such as TY-RAP brand cable ties or CATAMOUNT brand straps.Although the boot does limit the degree of movement in a wetenvironment, the boot allows the inner mechanisms of the conduit and theelectrical wiring to remain dry.

The disclosed device is preferably constructed of a molded ABS plasticor PVC. If the inner sleeve 4 is one solid piece, it may be formed froma tubular piece of plastic that has been heated and placed over a moldto form the larger ends. Alternatively, it may be made from two halfpieces of molded plastic that are fused together with heat or anadhesive. If the inner sleeve 4 is constructed of two or more piecesjoined together at a center joint 7, the center joint 7 would be madefrom two separate portions of molded plastic that are fused togetheraround the larger end of the inner sleeve 4.

While the invention has been described with respect to a limited numberof embodiments, those skilled in the art, having benefit of thisdisclosure, will appreciate that other embodiments can be devised whichdo not depart from the scope of the invention as disclosed herein.Accordingly, the scope of the invention should be limited only by theattached claims.

The terms “comprising,” “including,” and “having,” as used in the claimsand specification herein, shall be considered as indicating an opengroup that may include other elements not specified. The terms “a,”“an,” and the singular forms of words shall be taken to include theplural form of the same words, such that the terms mean that one or moreof something is provided. The term “one” or “single” may be used toindicate that one and only one of something is intended. Similarly,other specific integer values, such as “two,” may be used when aspecific number of things is intended. The terms “preferably,”“preferred,” “prefer,” “optionally,” “may,” and similar terms are usedto indicate that an item, condition or step being referred to is anoptional (not required) feature of the invention.

The invention has been described with reference to various specific andpreferred embodiments and techniques. However, it should be understoodthat many variations and modifications may be made while remainingwithin the spirit and scope of the invention. It will be apparent to oneof ordinary skill in the art that methods, devices, device elements,materials, procedures and techniques other than those specificallydescribed herein can be applied to the practice of the invention asbroadly disclosed herein without resort to undue experimentation. Allart-known functional equivalents of methods, devices, device elements,materials, procedures and techniques described herein are intended to beencompassed by this invention. Whenever a range is disclosed, allsubranges and individual values are intended to be encompassed. Thisinvention is not to be limited by the embodiments disclosed, includingany shown in the drawings or exemplified in the specification, which aregiven by way of example and not of limitation.

All references throughout this application, for example patent documentsincluding issued or granted patents or equivalents, patent applicationpublications, and non-patent literature documents or other sourcematerial, are hereby incorporated by reference herein in theirentireties, as though individually incorporated by reference, to theextent each reference is at least partially not inconsistent with thedisclosure in the present application (for example, a reference that ispartially inconsistent is incorporated by reference except for thepartially inconsistent portion of the reference).

1. A device for coupling a first conduit and a second conduitcomprising: a. a male end configured to be inserted into the coupling ofa first conduit; b. a coupling end configured to receive a secondconduit; and c. at least two joints each capable of permitting movementin an axial direction and at an angle relative to each conduit.
 2. Thedevice of claim 1 further comprising a jacket for preventing intrusionof liquids into said device.
 3. The device of claim 1 wherein said firstconduit and said second conduit are rigid non-metal conduits.
 4. Thedevice of claim 1 further comprising a center joint situated between themale end and coupling end and capable of permitting movement in an axialdirection and at an angle relative to each conduit.
 5. A device forconnecting a first conduit to a second conduit comprising a first jointhaving a first end configured to receive a conduit, said first jointcapable of permitting movement along the axis of the conduit and at anangle relative to the conduit, and a second end configured to receive asecond joint, said second joint capable of permitting movement along theaxis of the second conduit and at an angle relative to the secondconduit.
 6. The device of claim 5 further comprising a jacket forpreventing intrusion of liquids into said device.
 7. The device of claim5 wherein said conduit is rigid non-metal conduit.
 8. A device forcoupling a first conduit and a second conduit comprising: a. a male endconfigured to be inserted into the coupling of a first conduit; b. acoupling end configured to receive a second conduit; c. an inner sleevesituated between the male end and coupling end, said inner sleeve havinga flared coupling side and a flared male side; d. a coupling end adaptersub-assembly partially surrounding the flared coupling end such that theflared coupling end can move freely within said coupling end adaptersub-assembly in an axial direction relative to said coupling end andangularly relative to said coupling end; e. a male end adaptersub-assembly partially surrounding the flared male end such that theflared male end can move freely within said male end adaptersub-assembly in an axial direction relative to said male end andangularly relative to said male end.
 9. The device of claim 8 whereinthe inner surface of the inner sleeve is curved where the flared maleend meets the inner sleeve and where the flared coupling end meets theinner sleeve.
 10. The device of claim 8 wherein the flared male end andflared coupling end are each curved inwardly toward the axis of theinner sleeve.
 11. The device of claim 8 further comprising a jacketsurrounding said coupling end adapter sub-assembly, said male endadapter sub-assembly, and said inner sleeve.
 12. The device of claim 11wherein said jacket is secured with metal straps.
 13. The device ofclaim 11 wherein said jacket is secured with plastic ties.
 14. Thedevice of claim 8 further comprising a center joint capable of allowingaxial or angular movement.